The present invention relates generally to batteries, and more particularly, to thin lithium batteries.
Thin batteries are typically constructed with an alkali metal anode, a non-aqueous electrolyte, and cathodes of metal oxides. Lithium is most often used as an anode material because it has a low atomic weight and it is highly electronegative. Such thin batteries have a high energy density, a long shelf life and operate efficiently over a wide range of temperatures. As a result, such batteries find advantageous application in a wide variety of electronic devices.
In the past, thin batteries have been manufactured using electrolytes containing volatile solvents. Such solvents tend to evaporate rapidly and therefore require special handling and manufacturing processes. In this respect, once an electrolyte is prepared, it must be used quickly in the manufacturing process as such electrolytes have relatively short useable lives.
The present invention overcomes the problem of using volatile solvents in an electrolyte and provides a cathode/electrolyte slurry with little volatile solvent content having a long shelf life and usability.
In accordance with the present invention, there is provided an electrochemical cell comprised of a lithium-containing anode, and a cathode slurry comprised of 1) about 60% to about 70% by weight chemical manganese dioxide; 2) about 5% to about 10% by weight carbon; and 3) about 25% to about 35% by weight of an electrolyte consisting essentially of ethylene carbonate, propylene carbonate and triflate salt.
In accordance with another aspect of the present invention there is provided a cathode slurry for use in a lithium battery comprised of: 1) about 60% to about 70% by weight chemical manganese dioxide; 2) about 5% to about 10% by weight carbon; and 3) about 25% to about 35% by weight of an electrolyte comprised of: a) about 10% to about 40% by weight ethylene carbonate; b) about 60% to about 90% by weight propylene carbonate; and c) about 0.5 to about 1.5 moles of triflate salt.
It is an object of the present invention is to provide a thin lithium battery.
Another object of the present invention is to provide a thin lithium battery containing an extrudable cathode/electrolyte slurry.
A still further object of the present invention is to provide a battery as described above, wherein the cathode/electrolyte slurry is essentially not volatile.
A still further object of the present invention is to provide a battery as described above, wherein the cathode/electrolyte slurry has an extended shelf life prior to manufacturing the battery.
Another object of the present invention is to provide a cathode/electrolyte slurry for use in lithium batteries.
These and other objects and advantages will become apparent from the following description of a preferred embodiment of the invention, taken together with the accompanying drawings.